What happens in the field stays in the field…until now.

Adventures of a Red Sea diver

This week on Dispatches, we are excited to welcome Alysse Mathalon, who adds a point to a brand new area of our map as she tells us about her adventures doing fieldwork in Israel’s Red Sea!

When I first accepted my Master of Science research project, I had no idea what I would be diving into – literally. I knew that there would be diving involved, that my dive site would be accessible by boat, and that I would be doing a lot of fieldwork. This combined with the location of the project, in Eilat, Israel, on the Red Sea, was enough for me to accept the opportunity and not look back. I got myself to Eilat four days after officially accepting the position.

A view of the Red Sea in Eilat, Israel. A strong wind event resuspended shallow sediments, making the water murky. Mountains in the frame are in Aqaba, Jordan.

Eilat is a spectacular place. Situated at the southern point of Israel’s Negev Desert, it is surrounded by mountains as old as 500 million years. From its short coastline there are 3 countries in view; bordering from the north is Jordan, from the south, Egypt, and just across the narrow sea is Saudi Arabia. To make it even more extraordinary, beneath the sea surface are some of the most northern coral reef ecosystems in the world.

Eilat is located in a desert climate, where the weather is hot and sunny the majority of the time. However, rains can shower unpredictably and cause flashfloods in the otherwise silent and still desert. Dry river beds transform into rushing rivers, flowing seaward. My supervisors were fascinated by this unique phenomenon, which can bring tens of thousands of tonnes of sediment into the Red Sea in hours. Little is known about the frequency and magnitudes of flashfloods in this region, as such events have only been documented in the past 24 years. Flashfloods are important because they supply large amounts of sediment from land directly to the sea. The presence of flood sediments within the seafloor can therefore help paint a picture of past climatic events.

Flashflood flowing into the Red Sea in October 2016.

For our research project, we looked to the sediment layers below the seafloor to tell us stories of flashflood history. We asked whether it was possible to find flashflood deposits in the seabed from the previous 2000 years. First, we had to try and determine if flashflood deposits were actually getting preserved within the seafloor. This is where I came in. I set out to discover what happened to flood sediments after they settled on the shallow seafloor. Were they being removed by water currents, or being redistributed by fish? Were animals in the sediment mixing them up, destroying their pristine layering and making them unrecognizable?

To answer these questions, we conducted underwater experiments at a research station 13 metres below the sea surface, just offshore of the main location where flashfloods entered the sea. Here, instead of the vibrant coral reefs in the shallow waters by the marine institute, the waters were murky and the seafloor was packed with sediment.

On a field dive after a year and a half of experience. Neutral buoyancy? Check!

Upon arriving in Eilat, I immediately got my dive certification, as I had to jump right in and start the experiments. My supervisors now admit that they were slightly concerned about my diving skills; I was not the most graceful. A big part of being a good diver is being able to achieve neutral buoyancy. This means choosing the perfect balance of weight versus air in your diving vest, so you are hovering in the water. Each time I failed to be neutrally buoyant I would crash down onto the seafloor, and plumes of sediment would rise up, driving the visibility to zero. Diving in this challenging environment so frequently pushed me to become a much better diver, quickly.

The PhD Candidate and I about to jump into the water for a dive! We are pretty happy about it .

Throughout the project I brought many fellow researchers and friends along to help out with the experiments. We usually had to carry armloads of supplies on our dives to collect our samples. We became expert silent communicators, and we were highly determined to achieve our dive goals each time.

However, despite our determination, some frightening things happened down there that put me in ‘fight or flight’ mode. Once, we became so disoriented by the murky water that we didn’t know which way was up. We lost countless lab supplies, and had to avoid poisonous animals such as huge lion fish and potentially deathly scorpion fish. We spent hours upon hours under water at that station, and surfacing from those dives was always a glorious feeling. If we were extra lucky, on our way back to the marine institute we would stop by the Dolphin Reef to say hello to the dolphins, who live in a partially enclosed area of the sea.

Poisonous scorpion fish making himself at home in our equipment.

I am so grateful for my exciting fieldwork experiences, and for all of the outstanding people and friends I got to share those adventures with. If you have an opportunity to do fieldwork, even if you aren’t necessarily passionate about the purpose of the fieldwork, I would still recommend doing it. Communicating in a field setting is an incredible way to get to know people. Team work is ample, and being out in the natural world feels so messy, and challenges you to adapt. I learned a lot, and grew through those experiences. I wish you all the best in your field adventures. Happy fieldwork!

Alysse grew up in Toronto, Ontario, and got her first taste of the Atlantic Ocean while visiting her grandparents in Florida throughout her childhood. She decided to study marine biology during her undergraduate degree at Dalhousie University, and once she started, she never looked back. She is fascinated by ocean life, and has developed a passion for promoting ocean sustainability. During her undergraduate degree she published a scientific study quantifying microplastic pollution in sediments and mussels in Nova Scotia. This summer, Alysse is working for the Ontario Government as a Stewardship Youth Ranger Team Leader. She will guide high school students in carrying out environmental projects in the field. When it comes to the water, Alysse enjoys surfing, swimming, snorkeling, and going for fun dives!